DaveS

If you want 0.25" or better then find yourself a S/H ASA DDM. But finding hens' teeth might be easier. Unless you can afford a DDM100 at in excess of £25k

Yep, that would be a possibility, capture the RGB at bin 2 and 0.92 "/px, and the Luminance at bin 1 0.46"/px to pick up any detail that might be lurking below the bin 2 resolution.. The 533 does have some attractive features, but whether they are £1,149 attractive is another matter.

To expand on my previous post (From my phone), I have the 533 and the SX 694 in Stellarium and have been playing with the FoV. However, if the 694 at ~0.46"/px is silly, then the 533 at ~0.38 "/px is downright ludicrous. I could bin it at 2x2, but that would be 0.76"/px, at which point I might as well use the G3 16200 at bin 1 and crop. In any case, this is just a project to go after as many of the Hickson Compact Groups that are doable from here. It's not a major research project so probably not worth spending any money on. Again I thank all contributors for their posts.

I've looked at the 533, but I'm not going to be buying any more kit for the foreseeable. With our rubbish weather there's no point. In fact I wonder if there's any point in astronomy at all from our swamp of a country.

An update! The sky has cleared just enough and for long enough for me to run an autofocus check. And it worked! Yay! So that was the problem, as I suspected it was a driver issue, the "Enable 3x3 binning" box had to be ticked. No need to blow £1500 that I haven't got. Many thanks for all your input.

I ran the parameters of the ODK and ASI 294 through the Astronomy Tools calculator and got a figure of 24.5 mm, while the Baader filters run 26 mm. But I may have found one issue, the Sequence autofocus wants to bin 3x3 for the initial star find, and I had overlooked a bin 3x3 tick box in the SX driver, but won't be able to check if I've solved the problem until we get another clear night, and none are forecast this week.

Although my visual astronomy is only casual (I'm 99.99% imager) I did have a pair of distance glasses made up by my optician as an alternative to my varifocals and find them a huge improvement both for just eyeballing the sky and using a pair of bins. I have quite a complex prescription with short sight, astigmatism, and prism.

Wow, nobody has any issues at all! Magic!

Yes, I know it's a bit like apples and oranges, but the plate scale is about the same (And similarly barking) while the FoV is significantly wider. The origin of my query is from putting my old SX Trius 694 on the ODK 12 (Yep, I said it was barking) to go after the HCGs which would be tiny in the FoV of my G3 16200. I have run into all kinds of issues, the main ones being having sufficient stars in the field for plate solving to get a meaningful fix, but more crucially the ASA Sequence autofocus is throwing so many issues as to be dysfunctional. I suspect driver conflicts, but don't know enough to sort them out. On paper the ASI 294 *should* be a better camera, with lower read noise, higher QE and higher DR. With the short BF, and on a ZWO FW I think I will be able to "get away with" the 1.25" Baader filters that are already in said wheel. BUT... There's always a "gotcha" , and I was wondering what gotchas I should be aware of, and which might be a deal breaker. I am aware that the ASI 294 has amp-glow which will need Dark Frame calibration. The Trius 694 just needs Bias frames.

Holy Moley!

I would like to see a Hydrogen Balmer filter passing the H-alpha, beta, and possibly, the Gamma line as well. This would enable OSC imagers to add the HII regions of galaxies in something like their true colours, which isn't bright red. It would also give mono imagers more signal to play with.

This is a framing check I did on HCG 44. 12 x 300 subs with I know not what filter. The sequence specified Lum, the FITS header says Blue, but the Lum was in the light path when I took the train off the telescope for cleaning prior to getting keeper Flats. The only nasty stuff I can see are dust bunnies after calibrating with a Master Bias (Recommended in the SX 694 manual) This isn't for keeping BTW, in any case the moon was stupidly (My stupidity) close leaving a huge gradient.

I have a TG 365 cover over one of my rigs (The other is in an obsy) and find it very good. A couple of points though. It's worth getting some rope to tie round the cover in such a way as to prevent it from blowing off in high wind. Been there a couple of time, in one case I had to go out early in the morning in just my dressing gown to rescue a soaked telescope after the cover blew off in a storm. And if you can run a mains lead to the mount arrange an electric pet bed to go under the cover to provide gentle warmth that will keep condensation off.

Yes, quite possibly.

I'm not sure. I realised after I posted that I had the CCTV camera on, pumping out a flood of IR, plus I think I have identified a power supply issue, with a slightly loose connecter which I have changed. I ran an all-sky pointing model last night and didn't see anything untoward (Apart from moonlight noise) and did a framing check sequence on HCG 44 which likewise showed nothing unexpected.

"Open the observatory dome HAL" "I'm sorry Dave, I can't do that" "Why not HAL" "Because it's raining Dave" LOL

OK, the vertical streak looks like blooming, though I'm not seeing any saturated pixels in the histogram. Two (Very slight) positives are that my guess at the focus position was pretty close, and those diagonal shadows look to have gone.

Last night I was running trials after putting my very old SX Trius 694 on the ODK 12 for capturing some of the HCGs (0.46"/px. Yep, barking lol). Well, I didn't get very far, due to several reasons but this may be the deal breaker. A single 1 sec Luminance sub at -25C (Beta Geminorum used for Synch) And this horror is an autostretched version after Bias calibration. I've never seen anything like this from this camera, so have no idea what's going on. I just hope that I don't have a dead camera.

Well, I've just ordered a new workstation to take over from my current Charles Babbage steam powered jobby. Ryzen 7950, 64 GB RAM, 1TB and 2TB m2 SSDs and a Nvidia 6GB RTX 2000 graphics card. Possibly overkill at the moment but I want to be set up for any increase in hardware requirements without going mad with Threadripper or seriously expensive GPUs. the case has room for more conventional SSDs or HDDs (Remember those?)

It's been resolved.

For illustration I present Stephan's Quintet. Single 2 min subs in RGB From the Liverpool Telescope on La Palma. 2m mirror, f/10 but effectively 30 micron pixels and 90% QE.

Plain CLS filters are mainly for visual use so don't have to cut off the IR, but CCD / CMOS cameras have a significant sensitivity to IR so it needs to be blocked otherwise image bloat will occur.

A quick 2 hours on the Intergalactic Wanderer. Just given Dark Frame calibration and a humongous stretch. The diagonaal shadows are gone, just need to get some Flat Frames , and give the filters a clean.. Many thanks to @Oddsocks For identifying the cause of the problem, otherwise I'd be no nearer the solution.

This is the FoV with the Gsense 4040 on the 0.7M RC, again using Copeland's Septet as a reference And just to show that you don't need a big RC to get a narrow FoV, just need to be totally barking. My ODK 12 with my SX Trius 694

Many thanks for the link to that blog, yes figure 8 does look horribly familiar! Unfortunately OOUK only make telescope, they don't actually use them themselves, so egregious faults like this go unnoticed. Their "Customer Service" is notoriously poor, so perhaps customers just aren't bothering to report the issues.